Orbital Presence

Enter/leave transitions for a single conditional child using PresenceMotion presets.

Wrap one element (or one keyed fragment) and bind show to gate visibility. Pick a preset — PresenceMotion::fade, PresenceMotion::slide, etc. — then tune with PresenceMotion::with_duration and PresenceMotion::with_curve.

When respect_reduced_motion is true (default), injected styles honor prefers-reduced-motion: reduce. use_reduced_motion is available for imperative checks in consumers like hero parallax.